In December, the Illinois State Police did more than 60,000 background checks on firearms purchasers — an all-time record for any month in Illinois.

Last June, August and November all posted records for those months.

And on post-Thanksgiving’s Black Friday, Nov. 27, more than 5,000 background checks were done for gun sales — the most ever for a single day in Illinois.

Altogether, the Illinois State Police did 418,000 background checks on gun buyers in 2015, compared with 162,000 a decade earlier, records obtained by the Chicago Sun-Times show. The number of guns sold could be even higher, though: Each of those transactions could have involved more than one firearm.

Gun sales surged in 2013 and have been steadily strong since then, the records show.

“I don’t know if I would call it a surge, but business is growing,” said Randy Potter, general manager of GAT Guns in East Dundee in the northwest suburbs.

Potter said women are the fastest-growing segment of his business, which includes a firing range and a retail store.

He said gun sales soared in December because of fears stemming from the Nov. 13 mass shooting in Paris and the Dec. 2 massacre in San Bernardino, California. Buyers flocked to stores because of talk by President Barack Obama and Democratic presidential hopeful Hillary Clinton after those shootings about a need for greater gun control, Potter said.

The number of background checks the Illinois State Police did each month on gun buyers. Each background check can include more than one gun. December set the record for most background checks in a single month.

Chicago-area residents also were motivated to buy guns last year by the steady drumbeat in the news over bloodshed in the city, he said.

“It was a perfect storm,” agreed Lars Dalseide, a spokesman for the National Rifle Association.

Whitney O’Daniel, executive director of the Illinois Association of Firearms Retailers, said the concealed-carry law that took effect in 2014 was another factor driving up gun sales.

Gun sales rose nationally, too, according to FBI figures. December set a new monthly U.S. record of 3.3 million gun sales submitted to the bureau for background checks. That prompted U.S. Attorney General Loretta Lynch to tell Congress earlier this year the FBI has been overwhelmed by the gun checks.

The FBI does background checks to see whether a person is barred by law from buying a gun because of a felony record or mental illness. Those checks sometimes were taking longer than the three days the government is given to tell a dealer whether a buyer is OK to buy a firearm, Lynch said.

The Illinois State Police checks whether a potential gun buyer has a valid state firearm owner’s identification card. If the card is valid, the state police submit the person’s name and other identifiers to an FBI database and other state databases for a background check.

A source in the gun industry in Illinois said the state police often were taking more than the allotted three days to process background checks in December, but said, “It’s gotten better since then.”

Master Sgt. Matthew Boerwinkle, an Illinois State Police spokesman, said state law prohibits licensed firearms dealers from releasing a gun to a customer until the state police give their approval.

“Although turnaround times [for checks] did increase, ISP, with few exceptions, met the federal requirements for a three-day turnaround time,” Boerwinkle said.

He said the state has 10 firearm eligibility analysts and one supervisor in its Firearm Transfer Inquiry Program, which does the background checks.

It’s a matter of debate whether the rise in sales in Illinois and across the country is due to people buying their first guns or to people who have a gun and are buying more.

Gun-rights advocates say there’s been a surge in new owners, as evidenced by a rise in Illinois firearm owner’s identification cards — from about 1.2 million in 2009 to more than 1.9 million today.

But others point to the University of Chicago’s “Trends in Gun Ownership” report, a national survey released last March, that found the number of people reporting they own guns has steadily been dropping for decades.